Janete Gouveia de Souza

Castration and slaughter age effects on panel assessment and aroma compounds of the "mestiço" goat meat.

Cooked meat from castrated male and intact mestiço goats slaughtered at 175, 220, 265 and 310 days of age, were analysed by panellists and GC-MS. Slaughter age had a (P<0.05) effect on organoleptic qualities of goat meat. Scores for sensorial attributes were not different (P<0.05) for intact and castrated goats. A total of 87 compounds were identified and a further 21 were partially characterized by GC-MS. Hydrocarbons were presented in the highest relative amounts and all aroma isolates were dominated by products of lipid degradation. Total relative abundance of volatiles was identified at higher levels in the cooked meat from castrated goats than from entires. Meat from goats slaughtered at first age (175 days) was preferred by panellists and was found to have the lowest number of volatiles and total relative abundance.

Castration and slaughter age effects on fat components of “Mestiço” goat meat

Abstract The effect of castration and slaughter age on fat, cholesterol, phospholipids and fatty acid contents was determined for muscles of native Brazilian goat meat. Groups of castrated and intact “Mestico” goats were slaughtered at 175, 220, 265 and 310 days of age. Castration and slaughter age had a significant effect on total cholesterol and fatty acids contents. The cholesterol content increased with advance in slaughter age. Meat from castrated goat had a higher cholesterol content than that from intacts. Goat muscle contained mostly C18:1 (38–44%), C18:0 (23–25%), C16:0 (18–21%), and C18:2 (4–6%) fatty acids. There were no differences in levels of saturated, unsaturated and polyunsaturated fatty acids among the four groups slaughtered at different intervals. Castrated goat meat contained significantly greater unsaturated and polyunsaturated fatty acids than that of intacts. Total fat and total phospholipids percentages ranged from 3.0 to 3.4xa0g/100xa0g and 10.6 to 11.1xa0mg/100xa0g, respectively for intact and castrated goats.

Influência da Idade de Abate e da Castração nas Qualidades Físico-Químicas, Sensoriais e Aromáticas da Carne Caprina

Groups of crossbred castrated and intact goats were slaughtered at 175, 220, 265 and 310 days of age. The effect of castration and slaughter age on physical-chemical, sensorial and aromatic properties was researched. Calcium content was influenced by castration; however, slaughter age had a significant effect on moisture, protein, iron, calcium and pH. Castration and slaughter age had no significant effect on phospholipids contents, but slaughter age affected the percentage of total cholesterol. Fatty acids were significantly affected by castration. Castrated goat meat contained highest unsaturated fatty acids percentage and, consequently, highest ration PUFA/SFA. There were no differences in levels of saturated and unsaturated fatty acids among the animals slaughtered at different ages. Slaughter age had a higher effect on organoleptic qualities of goat meat compared to castration. A total of 108 volatiles were presented in the extract of goat meat, they were identified as: 41 aliphatic hydrocarbons, 12 alicyclic hydrocarbons, 19 aldehydes, 9 benzenoids, 9 alcohols, 7 ketones, 4 sulphur compounds, 2 terpenoids, 2 esters and 3 other compounds. Highest numbers of volatile compounds were identified from castrated goats than from entires. Slaughter age affected more intensively the physic-chemical and sensorial characteristics of goat meat. Castration affected directly the volatile formation.

Exigência de lisina digestível para frangos de corte machos de 1 a 42 dias de idade

This study was carried out with the objective of estimating the nutritional requirements of digestible lysine for broiler from 1 to 42 days old. A total of 1,950 male Cobb chicks were used (750, 600 and 600 in pre-initial, initial and growing phase, respectively) with initial weight of 45.1 ± 0.6, 160.5 ± 2.4 g and 746.3 ± 10.7 g, respectively. The birds were distributed in a completely randomized design, using six treatments and five repetitions, with 25, 20, and 20 chicks per experimental unit in the pre-initial, initial and growing phases, respectively. The treatments consisted of a lysine-deficient basal diet that was supplement with L-lysine.HCl in order to contain six digestible lysine levels (1.10, 1.16, 1.22, 1.28, 1.34 and 1.40%; 0.92, 0.98, 1.04, 1.10, 1.16 and 1.22% and 0.815, 0.875, 0.935, 0.995, 1.055 and 1.115%, for the pre-initial, initial and growing phases, respectively). The characteristics evaluated were: feed intake, weight gain and feed conversion, weight and carcass yield and prime cuts, relative and absolute weight of edible viscera and abdominal fat. In all phases, there was a linear effect of digestible lysine levels on feed intake and quadratic effect on weight gain feed conversion. There was no effect of the digestible lysine levels on the absolute weights of carcass, heart, and abdominal fat, carcass yields, breast, thigh and drumsticks, and on the relative weights of the heart, liver, gizzard and abdominal fat. However, there was a quadratic effect on the absolute weights of the breast, drumstick, thigh and liver. Digestible lysine levels recommended for male broilers are 1.286; 1,057 and 0,998% in the pre-initial, initial and growing phases, respectively.

Requirements of digestible methionine + cystine for broiler chickens at 1 to 42 days of age

The objective of this work was to estimate requirements of digestible methionine + cystine for broiler chickens from 1 to 42 days of age. It was carried out four experiments for each one of the following phases: pre-initial, initial, growing and final. The birds were distributed in a completely randomized experimental design, with six treatments and six replicates. Treatments consisted of a basal feed for each phase, deficient in digestible methionine + cystine and supplemented with DL-methionine to supply six levels of digestible methionine + cystine, resulting in different digestible methionine + cystine:digestible lysine ratios. In the pre-initial phase, levels of digestible methionine + cystine did not influence feed intake and feed conversion. However, weight gain responded in a quadratic way. In the initial phase, levels of digestible methionine + cystine had decreasing linear effect on feed intake whereas weight gain and feed conversion were influenced in a quadratic manner. In the growth and final phases, feed intake was not influenced by levels of digestible methionine + cystine, but weight gain and feed conversion presented quadratic response. The levels of 0.873; 0.755; 0.748 and 0.661% of digestible methionine + cystine in the diet or the daily intake of 183; 575; 1,104 and 1,212 mg of digestible methionine + cystine are recommended for the pre-initial, initial, growth and final phases, respectively, which corresponds to the ratios of 71; 70; 76 and 72% of digestible methionine + cystine to digestible lysine.

Influência do óleo de linhaça sobre o desempenho e a qualidade dos ovos de poedeiras semipesadas

This experiment was carried out to evaluate the influence of the linseed oil addition in replacement of soybean oil in laying hens diets on performance and internal and external egg quality. A total of 192 laying hens Bovans Godline line with 29 week-old, were distributed to six treatments, that consisted of a control diet (without vegetal oil) and of five diets containing 2% of linseed oil in replacement of 0, 25, 50, 75 and 100% of soybean oil, generating levels of 0.0, 0.5, 1.0, 1.5 and 2.0 % of linseed oil in the diets. The evaluated parameters were: production (PROD), egg weight (EW) and mass (EM), feed:egg mass ratio (FEM) and feed:egg dozen ratio (FED), albumen, yolk and shell weights and percentages, specific gravity, albumen and yolk dry matter, ashes and protein, yolk cholesterol and coloration. The production , EW, EM, FEM and FED, as for internal and external egg quality, were not influenced by the linseed oil levels in the diet. Likewise, no effect was observed on egg chemical composition and only yolk coloration was intensified with the levels above 1% of linseed oil in the diet. The addition of up to 2% f linseed oil on diet did not alter the performance on semi-heavy laying hens, and the internal and external egg quality and cholesterol.

Exigências de lisina digestível para codornas japonesas na fase de postura

The objective was to estimate the nutritional requirements of digestible lysine for Japanese laying quails. Two hundred and forty Japanese quails were allotted to a completely randomized block designs, with five diets, with six replications of eight birds each. Diets consisted of a basal ration deficient in lysine and supplemented with five levels 0.88, 0.96, 1.04, 1.12 or 1.20%) of digestible lysine. Feed consumption, egg production, egg weight and egg mass, feed conversion by egg mass (FCEM) and by dozen egg were evaluated. It was also evaluated, albumen weight, yolk weight and shell weight, percentages of albumen, yolk and shell and egg specific gravity. Dietary digestible lysine level linearly influenced feed intake, while egg production was affected in a quadratic faction by digestible lysine levels. The other characteristics were not affected by dietary digestible lysine levels. Dietary digestible lysine requirement for Japanese laying quails was estimated in 1.03%, which correspond to a daily intake of 292 mg of digestible lysine.

Carne caprina de animais mestiços: estudos do perfil aromático

The volatile profile of cooked goat meat was analysed using meat from castrated and intact animals slaughtered at 175, 220, 265 and 310 days. A total of 108 volatiles was detected and from them 69 was identified and a further 39 were partially characterised by GC-MS. The volatile profile was composed by hydrocarbons aliphatic and alicyclic, aldehydes, benzenoid compounds, alcohols, ketones, terpenoids, esters and sulfur compounds. Hexadecanal, benzen, heptane and octadecanal were among the volatiles with highest relative abundance. In both qualitative and quantitative analyses extracts from castrated meat had higher production of volatiles. The total number and the relative abundance of different classes of compounds seemed not to be cleared affected by slaughter age factor.

Nutritional requirements of digestible methionine+cystine for Japanese quails in production phase.

This experiment was carried with Japanese quails in the egg production phase with the objective of determining the requirements of digestible methionine + cystine (M+C) for higher production and egg quality. A total of 240 Japanese quails were distributed in a randomized complete block design. The basal diet was supplemented with different DL-methionine levels, corresponding to digestible methionine + cystine levels of 0.55, 0.61, 0.67, 0.73 and 0.79%. The characteristics analyzed were feed intake (g/quail/day), egg production (%), egg weight (g), egg mass (g/quail/day), feed conversion (dozen eggs/egg mass and kg feed/dozen eggs), egg shell (% and g), albumen (% and g), yolk (% and g) and specific gravity (g/cm3). The digestible M+C level for Japanese quails was 0.696% in the diet, corresponding to a daily intake of 186.7 mg/quail.

Effect of different metabolizable energy and soybean oil levels in the diet of laying hens on the egg chemical composition and lipid profile

This study was carried out to evaluate the effects of increasing metabolizable energy and soybean oil levels on the egg chemical composition, total lipids and cholesterol contents and fatty acids profile in the egg yolk. Three hundred and sixty 29 week-old Bovans Goldline semi-heavy commercial layers were used during three periods of 28 days. A completely randomized design were used in a 3 × 3 double factorial arrangement with three soybean oil levels (1, 2 and 3%) and three metabolizable energy levels in the diet (2,600, 2,750 and 2,900 kcal/kg), totalizing nine diets with five replicates of eight birds. No interaction soybean oil × metabolizable energy levels was observed. The metabolizable energy levels did not affect any of the determined characteristics. The moisture, ash and protein contents in the egg yolk and albumen and the lipid and cholesterol contents in the yolk were not affected by the soybean oil levels in the diet, while linoleic acid (C18:3) and linolenic acid (C18:2) levels responded linearly. The use of 2,600 kcal ME/kg and 3% of soybean oil in the diet of laying hens with consumption of 120 g/bird/day is justifiable, since this feeding strategy improves the fatty acids profile of the egg.